I have noticed that many of the warbirds that are ultimately brought back to flying status are almost completely built from plans and modern repro parts. 40 years ago complete planes changed hands and either flew or sat at airports or were stuck into museums.
In the last 15 years or so there are almost no "complete" planes to be found. The hulks that are the basic source for a plane that may fly years later has almost no usable, safe parts. Wrecks change hands and some parts are salvaged but few airframes are brought back to flyable condition after an incident.
I remember seeing the Nakajima Oscar "hulk" at the Champlin museum several yea ago. All that there was left was the center section of the fuselage. The rest was gone aft of the cockpit, no engine or tail, wings gone at the roots. I believe the thing is flyable now but I know for sure that 99.8% of it is replicated.
So more planes are becoming replicas anyway so why not fly them as they are like the new Me 262s? It's rapidly approaching the point where replicated machines are cheaper than originals anyhow so let's fly those.